Continued wet season rainfall has kept Lake Okeechobee high.
Lake Okeechobee was 16.29 feet above sea level on Jan. 31, up from 16.23 feet the previous week. That’s bad news for the lake according to scientists.
RECOVER (REstoration COordination & VERification) is a multi-agency team of scientists, modelers, planners and resource specialists who organize and apply scientific and technical information in ways that are essential in supporting the objectives of the Comprehensive Everglades Restoration Plan (CERP). According to RECOVER, the lake’s normal ecological envelope ranges from 12 feet at the end of the dry season to 15 feet at the end of the wet season. The lake’s recovery envelope uses a low of 11.5 to 12.5 feet and a high of 14.5 to 15.5 feet.
At 15.5 feet, the lake’s marshes are completely inundated with water. As the lake level rises, water stacks up against the dike. While the U.S. Army Corps of Engineers assures the public the rehabilitated Herbert Hoover Dike can withstand the higher lake level, keeping the lake high damages the lake’s ecology.
The lake needs the lower levels for sunlight to reach the lake bottom, causing new submerged aquatic vegetation (SAV) to sprout. SAV provides critical habitat for the lake’s fisheries. The vegetation is the lake’s natural filter system to clean the water. In 2023, the lowest level the lake achieved was 13.7 feet, which meant there was no chance for SAV to sprout.
For the week of Jan. 22-28, surface water inflows from the north into Lake Okeechobee totaled 58,070 acre feet while direct rainfall into the Big O accounted for 5,030 acre feet. For that same period, 26,710 acre feet left the lake through evapotranspiration (a combination of evaporation and plant transpiration), 4,200 acre feet flowed south for irrigation and east coast water supply, and 8,960 acre feet flowed west to maintain the beneficial flow to the Caloosahatchee River.
The Calooshatchee River needs freshwater flow to maintain the optimal saline levels in the estuary. The U.S. Army Corps of Engineers has set the target flow for the river in the beneficial range of 2,000 cubic feet per second (cfs) measured at the Franklin Lock, which is more than 43 miles from Lake Okeechobee. If there is rainfall in the local basin, less lake water is released into the river through the Julian Keen Jr. Lock at Moore Haven. If local basin runoff meets or exceeds the 2,000 cfs target, no lake water is released.
For the seven-day period ending Jan. 31, about half the flow at the Franklin Lock was local basin runoff and half was lake water.
The next meeting of the South Florida Water Management District Governing Board has been scheduled for Feb. 8 at 9 a.m. The meeting agenda has not yet been released.